Abstract:
This disclosure depicts cathodo-luminescent devices utilizing a gas discharge as the source of electrons, and television display apparatus employing an X-Y matrix of such devices as the picture elements. In each embodiment illustrated, the cathodo-luminescent display devices are depicted as each comprising a two-section gas cell. A gas discharge, serving as the electron source, is established in a first section between cathode means and anode means. Free electrons generated in the first section are drawn through openings in the anode means by a high gradient field in a second section and accelerated into impingement with a phosphor disposed on a viewing screen. Establishment of a gas discharge in the second section is precluded by appropriate selection of certain dimensions, gas pressure and accelerating voltage according to Paschen''s law. Moderating means is provided in certain embodiments for causing the energy range of free electrons entering the second section to be narrow relative to the range of energies of free electrons generated in the gas discharge. A number of control grid arrangements and other features and details are disclosed.
Abstract:
A color television picture tube panel is fabricated of relatively thin sheet glass formed to define a substantially rectangular faceplate area surrounded by an upstanding flange having a fluted configuration over portions of its periphery. The end surface of the flange defines a seal edge for forming a glass-to-glass seal with a funnel having a seal edge of sufficient area to bridge the maximum peak to trough dimensions of the fluted portions. Methods of manufacturing such a panel are also described.
Abstract:
A PROCESS FOR RE-ETCHING THE APERTURES OF A COLOR CAHODE-RAY TUBE SHADOW MASK TO INCREASE THE DIAMETER OF EACH APERTURE BY AN AMOUNT DEPENDENT UPON ITS SPACING FROM THE CENTER OF THE MASK BY FLOWING A FLUID ETCHANT THROUGH THE MASK APERTURES AND CONTROLLING THE VELOCITY OF ETCHANT FLOW THROUGH THE APERTURES TO DIFFER FROM APERTURE TO APERTURE AS A FUNCTION OF THE SPACING.
Abstract:
A photographic replica of a shadow mask of given transmission, i.e., ratio of aperture area to mask area, is made with the transmission of the photographic replica of the mask being less than that of the shadow mask. Thereafter, the photographic replica is used in place of the mask for screening the elemental phosphor deposits on the faceplate of a color television picture tube. In the case of a black surround type color tube, the replica is used to initially photoexpose the matrix pattern of phosphor receiving areas and subsequently used to deposit the phosphors. When the screen is fully fabricated, the shadow mask is assembled in position and the photographic replica is discarded.
Abstract:
In forming a light-absorbing grille or mat for a black-surround color tube, the screen area is covered with clear but sensitized polyvinyl alcohol (pva) and is thereafter exposed to develop a family of pva dots individually covering an elemental area of the screen that is subsequently to receive a deposit of one of three phosphors, green, blue and red. The exposure step is accomplished with seven light sources one of which is positioned to simulate one of the electron guns of the tube and this source accomplishes first order printing or exposure of the pva layer. The remaining six light sources are symmetrically and equidistantly spaced with respect to the first light source to accomplish second order printing or exposure of the same elemental areas exposed by the first mentioned light source. In this fashion each elemental screen area that is to receive a phosphor deposit is concurrently subjected to exposure from seven light sources.